linux-kernel - [PATCH 3/7] x86/efi/32: Fix EFI on systems where the percpu GDT is virtually mapped

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Date:   Wed, 22 Mar 2017 14:32:31 -0700
From:   Andy Lutomirski <luto@...nel.org>
To:     x86@...nel.org
Cc:     linux-kernel@...r.kernel.org, Borislav Petkov <bp@...en8.de>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Thomas Garnier <thgarnie@...gle.com>,
        Andy Lutomirski <luto@...nel.org>,
        Matt Fleming <matt@...eblueprint.co.uk>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        linux-efi@...r.kernel.org
Subject: [PATCH 3/7] x86/efi/32: Fix EFI on systems where the percpu GDT is virtually mapped

__pa on a percpu pointer is invalid.  This bug appears to go *waaay*
back, and I guess it's just never been triggered.

Cc: Matt Fleming <matt@...eblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@...aro.org>
Cc: linux-efi@...r.kernel.org
Signed-off-by: Andy Lutomirski <luto@...nel.org>
---
 arch/x86/platform/efi/efi_32.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index 950071171436..3481268da3d0 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -68,7 +68,7 @@ pgd_t * __init efi_call_phys_prolog(void)
 	load_cr3(initial_page_table);
 	__flush_tlb_all();
 
-	gdt_descr.address = __pa(get_cpu_gdt_rw(0));
+	gdt_descr.address = get_cpu_gdt_paddr(0);
 	gdt_descr.size = GDT_SIZE - 1;
 	load_gdt(&gdt_descr);
 
-- 
2.9.3